Ufo

Ufo

(alt-text)

"It's a little low for a weather balloon; it might be some other kind." "Yeah. Besides, I know I'm the alien conspiracy guy, but come on--the idea that the government would care about hiding something so mundane as atmospheric temperature measurement is too ridiculous even for me."

Special 10th anniversary edition of WHAT IF?—revised and annotated with brand-new illustrations and answers to important questions you never thought to ask—out now. Order it here!